Aircraft and Registration
Schweizer S 269C, registration I-GUAN.
Date and Location
27 May 2002, at 07:30 UTC. Caresana (VC), Italy.
Description of Event
During an aerial work flight for antilarval substance spreading over rice paddies, while in translational flight at about 6 meters altitude, the pilot felt strong vibrations from the tail rotor. As a precaution, he performed an off-field landing. After landing, it was found that the tip of one tail rotor blade had broken off.
Operator and Flight Nature
Operator: Elisystem s.r.l., Rivanazzano (PV). Flight nature: aerial work (substance spreading).
Occupants and Damage
Only the pilot was on board. The pilot was uninjured. Damage was limited to one tail rotor blade.
Personnel Information
The pilot was male, Italian, 30 years old, holding a valid commercial helicopter pilot license and a valid medical certificate. He had 628 total flight hours, of which about 616 on type. He had 0 hours in the last 24 hours, 18 hours 40 minutes in the last 7 days, and 38 hours 43 minutes in the last 30 days.
Aircraft Information
The Schweizer S 269C is a single-engine helicopter with a maximum takeoff weight of 930 kg, length 9.40 m, height 2.66 m, and rotor diameter 8.18 m.
Meteorological Information
Visibility was more than 10 km, no wind, and 6/8 cloud cover.
Analysis
Laboratory examination of the damaged tail rotor blade indicated that the tip cap failure was probably caused by detachment of the resin beads securing the basal tip during operation. This material, flung outward by centrifugal force, likely breached the closing tip. The breaking and partial shedding of paint along the entire trailing edge, along with partial laminate fracture, showed that the blade had experienced significant deformation, mainly elastic, due to a strong aft-to-forward stress, probably from an impact. The investigation could not determine whether the impact occurred before or after the resin bead detachment.
Probable Cause
The cause was attributed to a technical factor, probably due to a strong stress on the tail rotor blade.
Safety Recommendations
None.